Smarter fertilising results in lower costs

To take advantage of the yield potential in cornfields, it is important to make good use of mineral fertiliser and organic fertiliser in addition to crop rotation, integrated plant protection, good soil structure, the right pH and the composition of topsoil.

NIBIO has investigated the effect of nitrogen on oats and barley by adding the entire amount of nitrogen in spring versus only some in the spring and the rest as partial fertilising. The researchers recommend 8–9 kg of nitrogen per decare in the spring and the rest as partial fertilising. This allows you to adapt fertilising to the needs of the crops throughout the season to a much greater extent.

The results show a yield increase when up to 12 kg of nitrogen per decare is used, but no noticeable yield increase when the amount of fertiliser was increased to 16 kg of nitrogen per decare. This means that 12 kg is enough, even at a yield level of over 600 kilos of corn per decare. This matches well with the fertiliser standards in NIBIO’s fertilising handbook.

There are big savings to be made by taking advantage of the soil’s stored phosphorous resources. If the soil is rich in nutrients and loamy, you can under-fertilise with phosphorous for a year. This is positive in terms of finances and the environment. At the same time, you should aim for a high soil humus content which provides good conditions for root growth and nutrient absorption.

NIBIO has also investigated organic waste to see how the nitrogen becomes available for the crops. The studies show that in solid waste the nitrogen is present in organic compounds, but is mainly present as ammonia in liquid waste. The amount of nitrogen that is released from different types of waste varies considerably, but they all have in common that the readily available nitrogen fraction is released after 10–20 days.